Embodiments of the present inventive concepts relate to a data processing technique, and more particularly, to a method of programming program bits in a memory cell array by using a bit sequence scheme in a memory device where an unit cell array constraint exists, and apparatuses performing the method.
A chalcogenide alloy is used as a phase change material used in a phase change RAM (PRAM), and the phase change material causes a reversible phase change between a crystal state (i.e., low resistance) and an amorphous state (i.e., high resistance) by Joule heating occurred by a current or a voltage supplied to the phase change material. Accordingly, the PRAM stores information by using resistance difference of a phase change material, which is occurred by the phase change. In terms of property of PRAM, the number of a plurality of write drivers, which may program a plurality of PRAMs included in a memory cell array during a program operation, is limited.